1. What is the main aim of descriptive statistics?
a. Reduce the number of scores to a smaller more typical dataset
b. Create a comparable dataset
c. Reduce the number of scores to one or two values that provide a description of some aspect of the dataset
d. Increase the dataset to represent a population
e. Provide a narrative interpretation of a dataset
2. Which of the following are measures that attempt to describe the typical score of a dataset (3 correct answers)?
a. Deviation
b. Mode
c. Median
d. Mean
e. Residual
f. Range
g. Frequency
3. Which of the following provides the best definition of a frequency when the term is applied to a dataset?
a. The number of occurrences for a range of values that a variable takes in a data set
b. The number of occurrences for zero values that a variable takes in a data set
c. The number of occurrences for one, or a range of values that a variable takes in a data set
d. The number of occurrences for the mean value that a variable takes in a data set
e. The number of occurrences of inappropriate values that a variable takes in a data set
4. Which of the following provides the best definition of the term relative frequency when the term is applied to a dataset?
a. The same as the percentage for a particular value a variable may take in a dataset
b. The number of occurrences of the mean value that a variable takes in a data set divided by the total number of scores in the dataset
c. The number of occurrences for one, or a range of values that a variable takes in a data set divided by the total number of scores in the dataset
d. The number of occurrences of negative deviations divided by the total number of scores in the dataset
e. The number of occurrences of positive deviations divided by the total number of scores in the dataset
5. For which type of data is the mode the most appropriate descriptive statistic?
a. Ordinal
b. Interval/ Ratio
c. Nominal
d. Textual
e. Quantitative
6. To work out the median by inspecting the scores what must you do first to the dataset?
a. Remove any negative values
b. Rank
c. Work out the mean
d. Count the total number of scores
e. Know the formula to use
7. What is the main difference between the median and mean?
a. The median uses the ranked values whereas the mean uses the frequencies
b. The median uses the ranked values whereas the mean uses the actual values
c. The mean uses the ranked values whereas the median uses the actual values
d. There is no difference
e. The median uses deviations whereas the mean uses the actual values
8. When calculating the median for a dataset consisting of an even number of scores (i.e. 2,4,6 etc.) which one of the following is correct?
a. Calculate the average value of the three middle ranked scores
b. Calculate the mean for the whole dataset which would provide the same answer in this instance
c. Calculate the average value of the two middle ranked scores
d. Calculate the mode and use instead
e. Choose either the upper or lower value of the two
9. Which of the following statements concerning the mean is incorrect?
a. The mean is not suitable for nominal data
b. The mean is sensitive to a single extreme value
c. The mean should always be used as the preferred measure to indicate a typical score
d. The mean is a more complex descriptive statistic than either the mode or median
e. The mean provides the most sensible result when the interval/ratio dataset has a symmetrical set of scores
10. The mean can be interpreted as?:
a. The centre of gravity of a dataset
b. The average of the mode and median values of a dataset
c. The weight of all the scores
d. The weight of all the positive deviations
e. The relative frequency with the highest value
11. In a positively skewed dataset the various measures suggesting a typical value lie in the following order
a. median -> mode -> mean
b. mode -> median -> mean
c. mean -> mode -> median
d. mean -> median -> mode
e. mode -> mean -> median
